
package org.apache.solr.search;

import java.util.List;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.StrUtils;
import org.apache.solr.request.SolrQueryRequest;
/**
 * Parse Solr's variant on the Lucene QueryParser syntax.
 * <br>Other parameters:<ul>
 * <li>q.op - the default operator "OR" or "AND"</li>
 * <li>df - the default field name</li>
 * </ul>
 * <br>Example: <code>{!lucene q.op=AND df=text sort='price asc'}myfield:foo +bar -baz</code>
 */
public class LuceneQParserPlugin extends QParserPlugin {

    public static String NAME = "lucene";

    @Override
    public void init(NamedList args) {
    }

    @Override
    public QParser createParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
        return new LuceneQParser(qstr, localParams, params, req);
    }
}

class LuceneQParser extends QParser {

    SolrQueryParser lparser;

    public LuceneQParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
        super(qstr, localParams, params, req);
    }

    @Override
    public Query parse() throws ParseException {
        String lqstr = getString();
        if (lqstr == null || lqstr.length() == 0) {
            return null;
        }

        String defaultField = getParam(CommonParams.DF);
        if (defaultField == null) {
            defaultField = getReq().getSchema().getDefaultSearchFieldName();
        }
        lparser = new SolrQueryParser(this, defaultField);

        lparser.setDefaultOperator(QueryParsing.getQueryParserDefaultOperator(getReq().getSchema(), getParam(QueryParsing.OP)));

        return lparser.parse(lqstr);
    }

    @Override
    public String[] getDefaultHighlightFields() {
        return lparser == null ? new String[]{} : new String[]{lparser.getField()};
    }
}

class OldLuceneQParser extends LuceneQParser {

    String sortStr;

    public OldLuceneQParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
        super(qstr, localParams, params, req);
    }

    @Override
    public Query parse() throws ParseException {
        // handle legacy "query;sort" syntax
        if (getLocalParams() == null) {
            String lqstr = getString();
            if (lqstr == null || lqstr.length() == 0) {
                return null;
            }
            sortStr = getParams().get(CommonParams.SORT);
            if (sortStr == null) {
                // sort may be legacy form, included in the query string
                List<String> commands = StrUtils.splitSmart(lqstr, ';');
                if (commands.size() == 2) {
                    lqstr = commands.get(0);
                    sortStr = commands.get(1);
                }
                else if (commands.size() == 1) {
                    // This is need to support the case where someone sends: "q=query;"
                    lqstr = commands.get(0);
                }
                else if (commands.size() > 2) {
                    throw new ParseException("If you want to use multiple ';' in the query, use the 'sort' param.");
                }
            }
            setString(lqstr);
        }

        return super.parse();
    }

    @Override
    public SortSpec getSort(boolean useGlobal) throws ParseException {

        SortSpec sort = super.getSort(useGlobal);
        if (sortStr != null && sortStr.length() > 0 && sort.getSort() == null) {
            Sort oldSort = QueryParsing.parseSort(sortStr, getReq());
            if (oldSort != null) {
                sort.sort = oldSort;
            }
        }
        return sort;
    }
}
